Apparatus for silencing pulsating gaseous currents



Au '18, 1936. J. BVLANCHARD APPARATUS FOR S-ILENCING PULSATING GASEOUS-CURRENTS Filed Nov. 28, 1933 2 Sheets-Sheet 1 0 i we w M a d ATTORNEY Aug. 18, 1936. J. BLANCHARD 2,051,675; APPARATUS FOR SILENCING PULSATING GASEOUS CURRENTS Filed Novfl 28, 1933 2 Sheets-Sheet 2 Patented Aug. 18, 1936 APPARATUS FOR SILENCING PULSATING GASEOUS CURBENTS Joseph Blanchard,

one-half to Cecil land London,

Gordon Vokes, London, Eng- England, assignor of Application November 28, 1933, Serial No. 100,135

InGreat Britain June 2, 1933 7 Claims.

This invention relates to apparatus for silencing pulsating gaseous currents.

It is an object of the invention to provide silencing apparatus combining ease and cheapness of construction combined with efilcient operation. It is a further object of the invention to provide a silencer wherein high silencing capability is combined with low back pressure.

A further object of the invention is to provide a silencer wherein the main path of the gaseous currents is no more restricted than at the inlet.

Various other objects and advantages will be apparent from the following descriptions of embodiments of the invention, and the novel features will be particularly pointed out in connection with the appended claims.

In the accompanying drawings,

Figures 1 to 3 are perspective views respectively of three difierent forms of silencer in accordance with the invention, parts being broken away in these views to show the construction oi. the silencers. I

In the form shown in Figure 1, the silencer comprises an outer cylindrical casing I havin end plates 2 and 3 provided with eccentric'inlet and outlet orifices 4 and 5 respectively. Within the casing I there are arranged a pair of frustoconical chambers 6 and I having reticulated walls. The chamber 6 connects with an inlet pipe 8 associated with the orifice 4, and the frusta are so formed that the smaller end of the chamber 6 connects with the chamber 1 by means of an' eccentric aperture in the base of the latter, and the smaller end of the chamber I connects with an outlet pipe 9 by way of the aperture 5. A deflector plate I0 is situated in the chamber 6 immediately within the aperture 4 and comprises two portions II and I2: the portion II of the plate is inclined to the longitudinal axis of the chamber and has an edge in contact with the internal surface of the chamber, while the portion [2 is arranged parallel to the longitudinal axis of the chamber.

Gases entering the silencer by the inlet pipe 8 strike the portion II of the deflector plate and are deflected on to the wall of the chamber -6, which they follow with a gyratory movement. After the gases have made a substantially complete circuit of the inner surface of the container, they impinge upon the under surface of the portion I I of the plate whereby the gyratory motion and forward pitch is accentuated. That portion of the wall of the chamber onto which the in- 55 coming gases are deflected by the deflector plate is left imperforate. The function of the portion I2 of the deflector plate is to prevent gas from escaping impingement upon the inclined deflecting surface by lateral motion after passing through the aperture 4.

A second deflector plate similar to plate III is arranged within the chamber 1 to impart gyratory motion therein to the gases entering from chamber 6. This plate maybe arranged to impart to the gases a gyratory motion similar to that 10 of which they partake in the chamber 6, orto impart a gyratory movement in the opposite sense.

The holes in the silencer chamber have little if any effect upon the general gyratory course of the flow, but tend to permit the formation of a partial vacuum or zone of relatively low pressure in the centre of the gyratory flow; the efiect is to flow by absorbing theexcess of pressure of of the pulsations. The space between the reticulated walls and the outer casing thus serves as a closed or substantially closed cushioning space, also serving as a sound insulator where it is most required. The space may, if desired, be filled with sound absorbing material e. g. steel wool or fibrous asbestos, or it may be filled with material adapted to absorb or react with any poisonous components of the gaseous mixture passing through the silencer.

Where the silencer is to be used with heavy oil or other engines requiringthe silencer also to act as a spark arrester, openings I3 with cover plates I4 may be provided for the removal of solid deposits from the outer cylindrical casing.

The form of silencer shown in Figure 2 also comprises an outer cylindrical casing I provided with end plates in which inlet and outlet pipes 8 and 9 are eccentrically mounted. In this form, however, an inner cylindrical chamber I5 is provided, supported within the casing I by a diaphragm I6. At the inlet end of the chamber I5 there is provided a deflector plate I'I formed from a substantially ovoid sheet by bending to form a substantially semi-circular portion I8 which is situated in a plane at rightangles dinal axis of the chamber, a substantially triangular portion 69 parallel to the longitudinal axis, and a portion 20 inclined to this axis in two planes as shown in the drawings. Some of the portion IS an aperture 2| chamber I5 and is shaped as shown to direct the incoming gases on to the portion 20 of the defiector plate on the side remote from the aperture then pass through the aperture 2 I. These gases to the longitu- 45 21; as shown by the arrows and continue along the inner surface of the chamber with a gyratory motion. A second deflector plate 22, constructed in a similar manner to the first, is situated the chamber 05 tened in position.

The form of silencer simple construction and drical casing I. These spheres are each formed of two hemispherical stampings and have reticulatedwalls. The inlet pipe 8 projects into the left 25, and is providedwith a deflector 21 that the openings I3 for the removal of solid deprovided'in any position suitable to 1. Apparatus for silencing pulsating gaseous currents comprising in combination a relatively closing the said spherical chamber.

2. Apparatus for portion substantially parallel to the longitudinal axis of the said chamberadapted to prevent gases escaping deflection by the said first portion, and an outer casing enclosing the said reticulated wall of the said chamber.

in said casing;

being formed aperture, at least ng gyratory motionto the gases therein.

7. Apparatus for silencing pulsating gaseous currents comprising a. pair of conical chambers one having a base formed with an eccentric orifice, the other one of which discharges into the other through gyratory motion within one of the gases so discharged.

JOSEPH BLANCHARD.

and a deflector 

